First off thanks to everyonefor their help thus far. I am almost done with my sherman and I have a wiring harness that I don't know what its for?? I have the Tamiya sherman (56014) with battle system. Here are two pictures. Any information would be greatly appreciated, as I have looked through the manual many times over and don't see a reference to the harness. Not even in the parts listing at the back of the manual.

That's the 'extension unit' which you don't need if you are using a 4ch radio. It's only used if you want to run your sherman with a 2ch radio.